1. The Air CH 15 Prentice Hall p.498-501 CH 15 Prentice Hall p.498-501 Around You At 15 15. 1ppt

2. What is Meteorology? The study of weather and the atmosphere. – Weather- the condition of Earth’s atmosphere at a particular time and place.

3. Earth’s Atmosphere Atmosphere is from two Greek words: Atmos and sphaira. It makes conditions on the Earth suitable for living things. Contains oxygen and other gases living things need. Is constantly changing

4. Earth’s Atmosphere Importance of the atmosphere: – The atmosphere helps keep the planet warm. Allows for liquid water. – Protects from dangerous radiation. – Burns up chunks of rocks (meteoroids) from space. (meteors)

5. Atoms- the smallest unit of a chemical element that retains the properties of that element. Molecules- formed by two or more atoms (elements) – Molecules combine to form Gases Composition of Atmosphere

6. What gas in the atmosphere makes up the highest percentage of air? – A. Carbon Dioxide – B. Oxygen – C. Argon – D. Nitrogen Composition of Atmosphere

7. Contains gases, some of which organisms need to live – Nitrogen – Oxygen – Carbon Dioxide – Water Vapor – Along with other gasses, particles and liquids. Composition of Atmosphere

8. Most abundant (#1) gas in the atmosphere One nitrogen molecule contains 2 nitrogen atoms. N 2 All living organisms need nitrogen in order to grow and repair body cells. Nitrogen

9. Nitrogen fixation must occur to convert N 2 into a form that plants can use. (Nitrates) Plants absorb the nitrogen from the soil. Animals eat the plants. Nitrogen

10. The second most abundant (#2) gas O 2 Oxygen is an important ingredient in the combustion process. – Burning uses oxygen rapidly. Oxygen reacts slowly with metal objects to produce rust. Ozone –three oxygen atoms O 3 – Ozone Layer in Stratosphere – Ozone Hole Oxygen

11. One molecule has one atom of carbon and two atoms of oxygen. Essential to life. – Plants must use CO 2 to produce oxygen. – Animals give off CO 2 as a waste product. Carbon Dioxide

12. Fossil fuels increase the amount of CO 2 in the atmosphere. Earth’s temperature rises as a result. Carbon Dioxide

13. Nitrogen and Oxygen make up 99% of the gases in the atmosphere Argon and Carbon dioxide make up most of the remaining 1% (trace gases) Other (Trace) Gases Other Gasses Percent by Volume Argon0.93 Carbon Dioxide0.036 Neon0.0018 Helium0.00052 Methane0.00015 Krypton0.00011 Hydrogen0.00005

14. Is in the form of a gas. – It is invisible, not the same thing as steam. Varies from place to place. – Desert, Polar Ice Caps Almost no water vapor. – Tropical Rain Forest Five % of the air may be water vapor Water Vapor

15. Plays an important role in Earth’s weather. Forms clouds when water condenses on particles in the air. Leads to precipitation Water Vapor

16. Real world air contains tiny solid and liquid particles of: – Dust – Smoke – Salt – Other chemicals Particles